Radial lip shaft seal

Abstract

A unitary radial lip seal assembly to provide a fluid tight seal between a shaft and a housing bore through which the shaft extends includes an annular rigid retainer, a resilient body portion secured to the retainer and defining at least one sealing lip to seal against the rotatable shaft and a sleeve bearing member supported by said seal assembly outboard of the sealing lip. In one form the bearing member is rigidly connected to the retainer, in another, it is resiliently mounted to provide shaft vibration dampening. In the latter embodiment, the bearing member includes a radial wall urged into frictional engagement with a radial wall of the resilient body to restrict rotation of the bearing member.

I claim: 
     
       1. A unitary radial lip seal assembly for disposition in sealing relation between a surface defining a bore in a housing wall and a rotatable shaft having a predetermined diameter extending through the housing bore to contain fluid within the interior of the housing comprising: a) a rigid annular retainer member including an axial wall and an annular radial flange joined to said axial wall;   b) a resilient annular body portion secured to said retainer member, said resilient annular body portion defining at least one radial sealing lip extending away from said annular retainer member, said sealing lip being shaped, dimensioned and adapted for providing sealing engagement with the shaft; and   c) a compression-resistant sleeve bearing member secured to said retainer member, said sleeve bearing member defining an inner cylindrical bearing surface shaped, dimensioned and adapted for being disposed in surrounding relation to the shaft and an outer cylindrical bearing surface shaped and dimensioned for disposition adjacent said retainer member axial wall, said sleeve bearing member being adapted for disposition between said axial wall and the shaft, said sleeve bearing member being positioned relative to said sealing lip such that said sealing lip is adapted to provide contact with the shaft intermediate said cylindrical bearing surface and the fluid in the interior of the housing.   
     
     
       2. A unitary radial lip seal assembly as claimed in claim 1, wherein said sleeve bearing member includes a radial outer portion defining spaced radial edges, and said retainer includes a radial flange and a retention flange with said edges of said radial outer portion of said bearing swedged therebetween. 
     
     
       3. A unitary radial lip seal assembly as claimed in claim 2 wherein said bearing radial outer portion further defines a cylindrical outer surface and said retainer includes an axial wall defining a cylindrical surface disposed in mating relation to said cylindrical outer surface of said sleeve bearing member. 
     
     
       4. A unitary radial lip seal assembly as claimed in claim 3 wherein, upon installation, said resilient annular body portion further provides for a static seal between said assembly and the housing. 
     
     
       5. A unitary radial lip seal assembly as claimed in claim 1 wherein said inner cylindrical bearing surface is sized relative to the predetermined diameter of the shaft such that, upon installation, the clearance therebetween is less than the expected amount of eccentric operation of the shaft relative to the bore in the housing, so that said lip seal maintains annular contact with and a fluid tight relation to the shaft. 
     
     
       6. A unitary radial lip seal assembly as claimed in claim 5 wherein the clearance between the cylindrical bearing surface and the shaft is less than 0.020 inches. 
     
     
       7. A unitary radial lip seal assembly as claimed in claim 1 wherein said sleeve bearing member is made of filled polyphthalamide (PPA). 
     
     
       8. A unitary radial lip seal assembly as claimed in claim 1 wherein said resilient annular body portion includes a bearing support portion;   said bearing support portion includes a radial surface; and   wherein said sleeve bearing member includes a radially outer portion defining a radial surface in frictional contact with said radial surface of said bearing support portion to preclude rotation of said bearing member.   
     
     
       9. A unitary radial lip seal assembly as claimed in claim 4, wherein the housing includes a section having a cylindrical wall surface provided for disposing said seal assembly therein, and said retainer member has an outer diameter less than the diameter of the housing inner cylindrical surface, so as to provide an annular clearance, wherein, upon installation, a section of said annular body portion is disposed in said clearance between said retainer member and the housing inner cylindrical surface to provide a static seal therebetween. 
     
     
       10. A unitary radial lip seal assembly according to claim 1 wherein said sleeve bearing member is sufficiently rigid so as to resist compression under the eccentric deflection action of the shaft. 
     
     
       11. A unitary radial lip seal assembly as claimed in claim 1 wherein said sleeve bearing member comprises at least one material taken from the group consisting of cast iron, powder metal composites, bronze filled polytetraethylene and thermoplastic polymers. 
     
     
       12. A unitary radial lip seal assembly as claimed in claim 1, wherein said rigid annular retainer member further comprises a metallic material. 
     
     
       13. A unitary radial lip seal assembly as claimed in claim 12 wherein said rigid annular retainer member comprises stainless steel. 
     
     
       14. A method of aligning a shaft relative to a bore in a housing wall which shaft is rotatably supported within a member to be secured to the housing wall comprising the steps of: 1) providing a unitary radial lip seal assembly which seal assembly includes: a) a rigid annular retainer member including an axial wall;   b) a resilient annular body portion secured to said retainer member, said resilient annular body portion defining at least one radial sealing lip adapted for providing sealing engagement with the shaft;   c) a compression-resistant sleeve bearing member secured to said retainer defining an inner cylindrical bearing surface, said sleeve bearing member being shaped, dimensioned and adapted for disposition in surrounding relation to the shaft, said sleeve bearing member further defining an outer cylindrical bearing surface adapted to provide radial support between said axial wall of said rigid annular retainer member and the shaft;     2) disposing said seal assembly in the bore in the housing wall;   3) inserting an end of the shaft through said bearing member and then through said at least one sealing lip after said seal assembly is disposed in the housing wall bore; and   4) retaining said member that rotatably supports the shaft adjacent the housing wall.   
     
     
       15. The method according to claim 14 wherein said retaining step further includes providing a snap ring for insertion into a groove in a cylindrical wall of the housing to restrict the axial movement of said seal assembly relative to the housing. 
     
     
       16. A unitary radial lip seal assembly for disposition in sealing relation between a surface defining a bore in a housing wall and a rotatable shaft extending through the housing bore to contain fluid within the interior of the housing comprising: a) a rigid annular retainer member, including an annular axial wall and an annular radial flange, defining a radial surface, said radial flange being joined to said annular axial wall;   a resilient annular body portion secured to said retainer member, said resilient annular body portion defining at least one radial sealing lip adapted for sealing engagement with the shaft and a bearing support portion having a radial surface, said bearing support portion defining a bearing support portion groove and including a lip portion spaced from said bearing support portion radial surface; and   c) a compression-resistant sleeve bearing member secured to said retainer member, said sleeve bearing member defining an inner cylindrical bearing surface adapted for disposition in surrounding relation to the shaft and being dimensioned and positioned relative to said sealing lip such that said lip is adapted to contact the shaft intermediate said inner cylindrical bearing surface and the fluid in the interior of the housing, said sleeve bearing member further defining an outer cylindrical bearing surface in frictional contact with said radial surface of said radially outer portion of said rigid annular retainer member to inhibit rotation of said bearing member, said bearing member further including a ridge for engagement with said bearing support portion groove, and said lip portion providing a bias to urge said radial surface of said sleeve bearing member radially outer portion into frictional engagement with said bearing support portion radial surface.   
     
     
       17. A unitary radial lip seal assembly as claimed in claim 16 wherein the annular area of said radial surface of said bearing member exceeds the surface area of said cylindrical bearing surface by the ratio of about 3 to 1.   
     
     
       18. A unitary lip seal assembly as claimed in claim 17 wherein the cylindrical bearing surface is sized relative to the shaft such that the clearance therebetween is less than the amount of eccentric operation of the shaft relative to the bore in the housing permissible for said lip seal to maintain a fluid tight relation to the shaft. 
     
     
       19. A unitary radial lip seal assembly as claimed in claim 18 wherein the clearance between the cylindrical bearing surface and the shaft is less than 0.020 inches. 
     
     
       20. A unitary radial lip seal assembly as claimed in claim 19 wherein said sleeve bearing is made of filled polyphthalamide (PPA).